Variable action tubular shaft



1938. G. E. BA RNHART 2,126,717

VARIABLE ACTION TUBULAR SHAFT Filed Jan. 26, 1933 19 F1510- 22W H ll- 23/-: 3 D FIEE- 6i Hp Q42 if FIEJZ- INVENTOR GEoPaE 5. 5A PNHA 127' WM/M ATTORNEY actual use.

Patented Aug. 16, 1938 UNITED STATES PATENT form-cs 8 Claims.

ments, such as ship masts, telephone poles,

stanchions, etc.

As is well known to those familiar with the art, tapered tubes, depending upon their use, are subjected to compression, bending, tension or combinations of two or all of these forces.

Telephon"poles, for example, are subjected to compression, and bending forces due to wire pull; archers bows are subjected to compression and bending; airplane struts are subjected to compression; and golf clubs are subjected to the combined forces of tension and bendin since the centrifugal force of the stroke causes tension in the shaft, and the head resistance and contact with the ball creates bending.

It is important, therefore, that structures of 4 this nature be formed so that the axis of greatest strength can be readily determined merely by an inspection of the shaft. My invention contemplates a tapered tubular structure formed in this manner, and a method of making same. i i' It isan object of this invention to produce an article of the general type referred to above which has a characteristic action, whip, or feel, and in which the action or feel may be anticipated from the external appearances of the article.

In golf shafts, for example, some players prefer to have the feel, as it is termed, near the head of the club, others prefer to have it near the handle, and this invention contemplates the production of golf shafts in a manner such that the so-called feel can be placed at any point in the'shaft, and an inspection of the shaft will immediately indicatefwhere the feel will be in For example, beads placed on the sides .of a golf shaft may be used to illustrate that the shaft is stiffest in a; plane at right an gles to a plane containing the two beads. This stiffens the shaft in one direction, and gives added control to the club head without too greatly reducing the flex of the shaft.

The resultscontemplated by this invention are obtained by grooving :or corrugating the shaft or other article so as to change itsv crosssectional shape. In some instances, the desired action may be obtained by grooves which extend the entire length of the shaft, the general cross-sectional shape, in such instances, remaining the same.

In addition to this, my invention contemplates the placement of grooves of different types, or a different arrangement of grooves, at different points, or in different regions along the length of the shaft so that in one portion of the shaft 10 the greater stiffness will be in another axial plane, disposed at right angles or at another angle to the first mentioned axial plane.

This particular construction finds special application in the manufacture of golf shafts, since the neutral axis may be varied at different points so as to absorb any sting which might be carried from the impact of the head up into the grip.

My invention also contemplates a novel type of grip which adds to the ease with which the club may be handled, and also assists in absorbing the shock or sting resulting from the impact. It is an important feature of this grip that it incorporates grooves, of the type referred to hereinabove, positioned so as to give the desired stiffness in the grip portion of, the shaft, and

filled with a yieldable material which provides a cushion for the thumb and fingers.

It is an important feature of this invention that the' 'strength or stiffness may be selectively D 'sitioiied' "about the desired axis without increasing ,Qrchanging in any way the weight of the shaft; In this connection, it should be pointed out that a shaft embodying my invention has greater strength in bending than a round shaft of the identical weight.

It is a further object of this invention, to produce golf shafts, the characteristics of, which may be embodied ina set or series to provide 40 what is known as a matched set, in which the matched characteristics are immediately apparent to the observer.

Although I have referred to a golf shaft more particularly hereinabove, and will confine the detailed description of the invention to a golf shaft, it is to be understood that the invention is not limited to this particular type of structural element, but that it may find special application in the production of dueling swords, fencing swords, bayonets, and the like, inthat the practice of the invention may be employed to give the desired action or Whip by the varying sectional shape, and, naturally, the hollow con-' struction gives light weight combined. with strength. I

The invention is also particularly adapted for use in connection with fishing rods for the same reasons as pointed out above, as for instance, the best shapes can be supplied which will best sustain bending, tension, compression, and other forces. Numerous other applications will be immediately apparent to those familiar with the art.

This invention also contemplates a novel method for grooving the elements contemplated by this invention, and particularly drawing in grooves by a drawing action on the metal.

The details in the construction of certain preferred embodiments of my invention, together with other objects attending its production, will be best understood from the following description of the accompanying drawing, which is chosen for illustrative purposes only, and in which Fig. 1 is an elevational view showing a golf club equipped with a shaft embodying my invention;

Fig. 2 is a plan section taken in the plane represented by the line 2-2 in Fig. 1;

Fig. 3 is a plan section taken in a plane represented by the line 3-4 in Fig. 1;

Fig. 4 is a plan section taken in a plane represented by the line 4-4 in Fig. 1;

Fig. 5 is a plan section taken in a plane represented by the line 5-5 in Fig 1;

Fig. 6 is a plan section taken in a plane represented by the line 6-6 in Fig. 1;

Figs. '7, 8, and 9 are side views showing tubular tapered shafts, grooved in accordance with my invention, and illustrating various types of grooves which may be employed;

Figs. 10, 11, and 12 are fragmentary sectional views further illustrating various types of grooves which may be employed in connection with my invention; and

Fig. 13 is an elevational view, partly in section,

illustrating one form of machine which may be employed in producing the article contemplated by this invention.

More particularly describing the invention as herein illustrated, reference numeral ll indicates a golf club which, as pointed out hereinabove, has been chosen to illustrate one application of the invention.

The golf club I I comprises a shaft l2, which has a head I3, and a grip portion II. The grip portion I4 is shown as being provided with a pair of oppositely disposed grooves or corrugations l6, which are positioned in a plane that lies substantially normal to the striking face of the club l3. These grooves, in addition to positioning the axis of, greatest stiffness in a plane which is normal to the striking face of the club, are adapted to receive rubber or other yieldable sections I! which provide cushions for the thumb and fingers. The grip portion of the club, of course, is covered in any suitable manner, as indicated at ii.

In this form of my invention, I show the grooves i6 as extending only part way into the gripping portion of the club. For some purposes, where it is desired to have a maximum stiffness of the extreme upperend of the groove, this arrangement is particularly suitable. It is to be understood, however, that the grooves might be made shorter or longer than illustrated.

In this particular form of shaft, I show in the portion indicated at A, which is just below the grip portion, a section provided with five grooves,

indicated at I9, as shown in the cross-section in Fig. 3. In this particular construction, the neutral axis of this section of the shaft lies along the line Xa so that the maximum stiffness of the shaft lies in a plane at right angles to the plane of maximum stiffness in the section shown in Fig. 2.

The portion A, in this form of my invention is followed by another segment B of the shaft, which has four grooves arranged in the manner shown in Fig. 4. This particular arrangement again reverses the position of the neutral axis so that the maximum stiffness in this section lies in a plane Xb at substantially right angles to the plane of maximum stiffness in the section shown in Fig. 3. The grooves i913 in the section B may be continuations of the four front grooves in the section A, the back groovesv having been discontinued.

The section B is followed by another section C, designed to given even greater stiffness to a part of the shaft at its lower end, such section having only two grooves, indicated at ISC, which may be thought of as being continuations of the two front grooves in section B. The last section of the shaft, indicated at D, which extends into the head, is shown as being a round.

The shape or form of the various grooves in the various sections may be varied, within-comparatively wide limits, depending upon the extremes desired in the particular action which these grooves will obtain.

In Fig. 7, for example, I have shown a groove 20 which is of uniform width throughout its length, and which may end abruptly as indicated at 2|. This groove may be of uniform depth, as indicated at 22 in Fig. 10, or it may be of gradually decreased depth, as indicated' at 23 in Fig. 11, in which event it might gradually Wash out as the diameter of the shaft decreases. On the other hand, the groove 20 of uniform width might gradually increase in depth as the diameter of the shaft decreases, taking the form shown at 24 in Fig. 12.

In Fig. 8, I show a groove 25, the width of which decreases as the diameter of the shaft decreases, and this groove, like the one shown in Fig. 20, may take any one of the three forms shown in Figs. 10 to 12 inclusive.

In Fig. 9, I show a type of groove 26, which gradually increases in width as the diameter of the shaft decreases, and this groove, like the ones shown at 20, may take the various forms shown in Figs. 10 to 12 inclusive.

It is to be understood, of course, that the form of shaft shown and described hereinabove is designed to produce one particular action or result. The arrangement of the grooves, however, as pointed out above, may be varied within comparatively wide limits to produce different actions, and, in some instances, the cross-sectional shape of the shaft in its grooved portion may remain the same throughout the entire length of the groove portion. In some instances, it might even be desirable to form the longitudinal grooves on a slight spiral about the shaft to obtain the required results.

In Fig. 11, I show somewhat diagrammatically one form of machine which may be used to produce the grooved article contemplated by this invention, and to illustrate broadly my method.

This machine may embody in a general way the principles of a tube drawing machine in that the shaft tobe grooved, which is indicated by reference numeral 30, is mounted in a come-along 3| whereby it is drawn through a grooving mech anism, generally indicated by reference numeral The grooving mechanism 32 is shown as comprising an upright support 33 which has an opening 34 through which the tube or shaft is adapted to be drawn.

The upright support 33 is mounted upon a base member 34 which is provided with a guide 35 adapted to be received in a shoe 36 on the bottom of a leg 31 which forms apart of a comealong. The shoe 33, which is secured to the base of the leg 31 through the medium of screws 38, is of a length equal to or slightly greater than the length of the shaft and has an inclined upper surface which I might term a cam, this surface being indicated by reference numeral 38.

The cam surface 38' extends below and is adapted to be engaged by a roller 39 mounted on the outer end of an arm 40 which is either secured to or forms part of a lever member 4|. The lever member 4i is pivotally mounted upon a bracket 42 secured to the upright support 33.

i The lever member M is shown as being in the nature of a stirrup or yoke, the upper portion of which supports a ring member 45 in a pin and slot connection indicated at dotted lines at 44.

The ring member 45 carries, what I may term, swinging roller members generally indicated at 46. These swinging roller members 46 comprise lever arms 41, the forward ends of which are provided with grooving rolls 48 adapted to engage the shaft 30, and the rear ends of which are provided with guide rolls 49 adapted to engage the surface of a'hollow guide cone member 50.

rolls into engagement with the shaft is positively limited by the engagement of the roller 39 with the cam surface 38'. This cam surface, moving with the come-along, regulates the depth of the grooves.

rollers 48, and the guide rollers 49, by virtue of.

their engagement with the conical surface 50. coordinate the depths of \the various grooves so that one is not deeper than the other.

The number of grooves may be regulated by varying the number of swinging roller units, and

the come-along may be rotated during a drawing,

operation to form spiral grooves on the shaft.

Although it is particularly desirable from the standpoint of the drawing action obtained and its attending strengthening and toughening properties to form the articles contemplated by this invention by a process of the type described above in connection with the machine shown in i Fig. 13, it will be apparent to those familiar with the art that the shapes desired may be obtained by other means.

For'example, it is possible to use tapered sections of metal shaped so that when they are pressed or drawn into the shaft they will give the desired shape to the groove. If it is desired The width of the grooves may be varied by changing the size and shape of the grooving to produce an ornamental shaft, designs may be cut on the grooving rollers 48, such designs being It is to be understood that, while I have herein described and illustrated one preferred form of my invention, the invention is not to be limited to the precise construction, as described above, but includes within its scope whatever changes fairly come within the spirit of 'the appended claims.

I claim as my invention:

1. A hollow, tapered shaft having a plurality of longitudinal grooves of different lengths therein, said grooves being arranged so as to vary the cross-sectional shape and the relative location of the neutral axis of said shaft at difierent portions of the shaft throughout its length.

2. A hollow, tapered shaft having a plurality of longitudinal grooves of different lengths therein, said grooves being arranged so as to vary the neutral axis of said shaft at different portionsof the shaft throughout its length, certain of said grooves being filled with a yieldable materiaL.

3. A hollow, tapered shaft having longitudinal grooves therein, said grooves being arranged so as to vary the cross-sectional shape and the location of the neutral axis of said shaft at different portions of the shaft, some of said grooves being of uniform width and uniform depth throughout their length.

4. A hollow, tapered shaft having longitudinal grooves therein, said grooves being arranged so as to vary the cross-sectional shape and the location of the neutral axis of said shaft at different portions of the shaft, some of said last mentioned grooves being of uniform width throughout their length and decreasing in depth as the diameter of the shaft decreases.

5. A hollow, tapered shaft having longitudinal grooves therein, said grooves being arranged so as to vary the cross-sectional shape and the'location of the neutral axis of said shaft at different points throughout its length, some of said grooves being of uniform width throughout their length and increasing in depth as the diameter of the shaft decreases.

6. A hollow, tapered shaft having longitudinal grooves therein, said grooves being arranged so as to vary the cross sectional shape and the location of the neutral axis of said shaft at different portions of the shaft and decreasing inwidth as the diameter of the shaft decreases.

7. A hollow, tapered'shaft having longitudinal grooves therein, said grooves being arranged so as to vary the cross-sectional shape and the location of the neutral axis of said shaft at different portions of the shaft, some .of said grooves being of uniform depth throughout their length and increasing in width as the diameter of the shaft decreases.

8. A hollow,'tapered shaft having longitudinal grooves therein, said grooves being arranged so as to vary the cross-sectional shape and the locaq tion of the neutral axis of said shaft at different portions of the shaft, some of said grooves being of increasing depth and increasing in width as the diameter of the shaft decreases.

GEORGE E. BARNHART.

-cross-sectional shape and the location of the 

